Confirm the option by selecting Yes and hitting enter (The test will run for 1 minute)

You can monitor the status of the batteries while the test is running by Hitting Escape to get back to the main menu

Select "Status" from the main menu
Scroll down the list to Battery Voltage.

Make a note of the Actual Battery Voltage and How low it goes during the test. When the test is completed this number will start climbing. Value should be as close to 192v as possible. Lower values indicate the batteries are getting weak.